Water traps are used to connect water receptacles with drains and sewers.
The most common type of trap is what is known as a S-bend trap.
Where there is adequate room, S-bend traps are readily installed and dismantled for maintenance purposes but where there is limited room, for example, where the trap is required to be installed in a pedestal or other form of shroud, installation becomes a difficult exercise.
In-line or so called xe2x80x9cbottle trapsxe2x80x9d have been proposed in the past in an effort to facilitate ease of installation and maintenance.
U.S. Pat. No. 3,725,964 describes an in-line trap having an inlet, an outlet, and an open top water seal container in a substantially concentric arrangement. The main objective of the inventor was not to minimize size, but to provide a structure which, it is said, can be readily dismantled for maintenance purposes. The trap described appears to be designed exclusively for a kitchen sink and would not be suitable for fitment to smaller diameter basin waste pipes, nor would it be readily adapted to retro-fitment to existing installations.
It is an object of the present invention to provide a water trap which is compact and can be produced to suit numerous installation requirements, particularly those where space is at a premium.
An orderly flow of water through water traps is highly desirable.
Any structure and arrangement of a trap which creates excessive syphoning as water passes through the trap is likely to drain out to below a satisfactory, or prescribed minimum, volume of entrapped water.
A further object of the present invention is to provide a water trap which promotes an orderly flow pattern of fluids passing through the trap and a controlled level of syphoning from the trap.
Further objects and advantages of the present invention will become apparent in the ensuing description.
According to the present invention there is provided a water trap comprising a substantially cylindrical outer casing having a flat top wall, a side wall and a frustoconical bottom wall, and an internal substantially semicircular open topped water seal container within the outer casing which occupies a half segment of the outer casing thus defining a second half segment region, the water seal container having a flat base and a top edge which terminates below the top wall of the outer casing defining a space between the top edge and the flat top wall of the casing, an inlet into the water seal container which passes through the flat top wall of the casing, abutting a side wall of the water seal container and terminating in close proximity to the flat base of the water seal container, the cross-sectional area of the inlet being constant over its length, an outlet from the frustoconical bottom wall of the outer casing which is offset and co-linear with the inlet, the inlet having a sink connecting nut and the outlet having an external O-ring seal, the invention characterized in that the cross-sectional areas of the inlet, water seal container excluding the inlet, the space above the top edge of the water seal container, and the region between the water seal container and the outer casing, progressively increase to assist water flow through the trap.
The axis of the outlet can be off set in relation to the axis of the outer casing.
The inlet can be fitted with a standard sink connecting nut.
The outlet can be provided with an external O-ring seal.
Elements of the trap can have the following cross-sectional areas (C.S.A.).
The body has a frustoconical portion preceding the outlet.